Quick Facts
- Ovarian cancer, especially at later stages, can be challenging to treat as it can become resistant to traditional platinum-based chemotherapies.
- Elahere addresses the gap in effective medications for those platinum-resistant cancers which express high levels of folate receptor α (FRα).
- To determine your eligibility for Elahere, your doctor must test your cancer for FRα expression. FOR1, the commercial version of this test, is readily available. If your FOR1 test is positive, it means that you have high levels of FRα and may benefit from Elahere.
- Key questions to ask doctors include platinum-resistance status, FRα protein testing results, need for additional testing, and suitability for Elahere treatment.
Now, a breakthrough drug, Elahere (generic name: mirvetuximab soravtansine), may offer a viable, effective treatment option to those patients with platinum-resistant ovarian cancers whose tumor cells express high levels of folate receptor alpha (FRα) proteins.
Read MoreOvarian Cancer Is A Significant Medical Challenge
Ovarian cancer is among the most lethal forms of cancer, accounting for more deaths than any female reproductive system cancers. Among women diagnosed with this disease, only 47% will survive beyond five years from their initial diagnosis. In the United States, approximately 20,000 women are projected to receive an ovarian cancer diagnosis in 2022, contributing to an estimated 13,000 fatalities.RELATED: Ovarian Cancer: Overview
What Is Platinum-Resistant Ovarian Cancer?
Platinum-based chemotherapy, such as carboplatin and cisplatin, is crucial in treating ovarian cancer. However, around a quarter of women with ovarian cancer do not respond to these treatments upon initial diagnosis, and even those who do respond often develop resistance over time.
When ovarian cancer returns within 6 months of initial therapy, it is deemed platinum-resistant ovarian cancer. Unfortunately, the prognosis for cancers resistant to platinum-based therapies is suboptimal resulting in an average survival of fewer than 12 months.
There is thus a pressing need for effective treatments for patients with such cancers and Elahere is poised to address exactly this. Considering that no new and effective medication has been introduced for such patients since 2014, Elahare is a tremendous step forward in improving the outcomes for patients.
However, it is important to note that “it is only [FDA-]approved for people that have a high level of folate expression,” stresses Dr. Noelle Cloven, a preeminent gynecologist-oncologist at Texas Oncology.
Do All Ovarian Cancers Express Folate Receptors (FRα)?
FRα is a protein molecule found on the outside of ovarian cancer cells. More than 70% of ovarian cancers express this protein at the time of initial diagnosis. However, 80% of the cancers that come back after initial treatment express this protein. Thus, FRα expression can be a marker of a more aggressive disease that may be resistant to traditional treatments and likely to return.
Do The Levels Of Folate Receptors (FRα) Matter?
The levels of FRα proteins expressed by a patient’s cancer are important. These levels can be quantified using a special test called immunohistochemistry (IHC). “[This] is a test that is now [easily] available. Your doctor can order [this test] in tissue from your previous surgery,” says Dr. Cloven. The commercially available version of the test is called “FOLR1.”
More specifically, this test uses a protein molecule that binds to FRα, effectively “staining” any cells that have the folate receptor. The intensity of this cellular staining is then read by a trained pathologist, who assigns it a score ranging from 0 to +3, with 0 representing no staining, +1 weak staining, +2 moderate staining, and +3 strong staining. The aggregate results of the test are reported as either positive if more than 75% of the cancer cells stain either moderately or strongly, or negative if less than 75% of the cells stain with moderate or strong staining.
Dr. Cloven notes, “[Elahere] is only approved for people that have a high level of folate expression. You have to have… 75% expression [a positive test] because [it is patients with those levels] that this drug works [best] on.”
While 75% may sound like a high number that only a few patients meet, Dr. Cloven relates her personal experience, saying “I’ve had very good success with finding a lot of patients [who] have high levels of expression.”
How Effective Is Elahere?
The effectiveness of Elahere was studied in patients with FRα-positive, platinum-resistant ovarian cancers who have received one to three prior systemic therapies. Of these, 31.7% of the patients received at least some benefit from the drug. Breaking it down further showed that 4.8% of the patients had their tumors disappear completely, while 26.9% of the patients had a decrease in the amount of their tumor but not disappearance. On average, these patients experienced a therapeutic benefit for 6-7 months.
Dr. Cloven’s personal experience corroborates these results, “I’ve had patients that have been getting good responses.”
Is Elahere Right For You?
Your eligibility to receive the medication and benefit from it depends on many factors, as outlined above. To be a good candidate for Elahere, you must meet the following criteria:
- You must have undergone prior treatment with platinum-based chemotherapies, such as cisplatin and carboplatin, and deemed resistant to them. Your cancer is termed resistant if it returns within 6 months of therapy initiation.
- Your cancer must be tested for FRα expression. This can be done through the commercially available FOLR1 test. Sample tissue from your original surgery can be retrieved and sent for this test, so this step does not generally require new biopsies.
- The results of the FOLR1 test must indicate a high level of FRα expression (positive result). This is because only those with high levels of expression are currently known to benefit from this medication.
RELATED: Is The Drug Elahere An Option When My Ovarian Cancer Returns?
Questions to Ask Your Doctor?
- Is my ovarian cancer platinum-resistant?
- If so, what are my treatment options?
- Has my cancer been tested for the folate receptor α protein?
- If so, what did the results show?
- Do I need additional testing to evaluate whether I am a good candidate for Elahere?
- In light of my treatment history and test results, is Elahere a good treatment option for me?
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